The present invention relates to axle construction for railway type vehicles which run on spaced parallel tracks where the wheels carried on the axle rotate freely and independently of each other or may rotate together.
Wheel and axle constructions in common use in the railroad industry today include wheels fixed at opposite ends of a one piece axle where the two wheels rotate in unision, that is the wheels operate at the same speed so that, for example, in negotiating a curve one of the wheels drags while the other one operates at a higher rate of speed. The accumulated drag occuring or resulting from the half of the wheels dragging around a curve substantially reduces the efficiency of the motive means utilized to pull the train. Further, the action tends to wear out the track, loosen the track from the cross ties, and leads to unnecessarily early failure of the wheels.
The problem has been addressed in several prior art arrangements including U.S. Pat. No. 683,001-Robeson where an axle box was provided with bearings for axle sections, where the axles are actually physically separated from each other and contained within a housing which extends the distance between the two wheels and is received in openings in the wheels.
U.S. Pat. No. 441,014-Mahood provides an arrangement where a split axle is provided with a housing which is connected directly to the rail car between the wheels. U.S. Pat. No. 1,812,127-Wisner provides an arrangement where an axle is provided to be received in a housing which extends fully between the wheels and a tubular axle section.
U.S. Pat. No. 2,073,829-Brown provides an arrangement where the wheels are carried by axle members received in a central housing where again the axle assembly is received within a tubular axle assembly which extends from wheel to wheel.
No prior art arrangement is known where a simple self supporting housing is provided centrally between the opposed wheels and where one axle is received in the other axle with appropriate bearing means to allow independent rotation of the two shafts.